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From:   Hector Martin <marcan@marcan.st>
To:     linux-arm-kernel@lists.infradead.org
Cc:     Hector Martin <marcan@marcan.st>, Marc Zyngier <maz@kernel.org>,
        Rob Herring <robh@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
        Olof Johansson <olof@lixom.net>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Mark Kettenis <mark.kettenis@xs4all.nl>,
        Tony Lindgren <tony@atomide.com>,
        Mohamed Mediouni <mohamed.mediouni@caramail.com>,
        Stan Skowronek <stan@corellium.com>,
        Alexander Graf <graf@amazon.com>,
        Will Deacon <will@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Mark Rutland <mark.rutland@arm.com>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 09/25] arm64: entry: Map the FIQ vector to IRQ on NEEDS_FIQ platforms
Date:   Mon, 15 Feb 2021 21:16:57 +0900
Message-Id: <20210215121713.57687-10-marcan@marcan.st>
In-Reply-To: <20210215121713.57687-1-marcan@marcan.st>
References: <20210215121713.57687-1-marcan@marcan.st>
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From: Marc Zyngier <maz@kernel.org>

By default, FIQ exceptions trigger a panic. On platforms that need to
deliver interrupts via FIQ, this gets redirected via an alternative to
instead handle FIQ the same way as IRQ. It is up to the irqchip handler
to discriminate between the two.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>
---
 arch/arm64/kernel/entry.S | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index ba5f9aa379ce..bcfd1ac72636 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -547,18 +547,18 @@ SYM_CODE_START(vectors)
 
 	kernel_ventry	1, sync				// Synchronous EL1h
 	kernel_ventry	1, irq				// IRQ EL1h
-	kernel_ventry	1, fiq_invalid			// FIQ EL1h
+	kernel_ventry	1, fiq				// FIQ EL1h
 	kernel_ventry	1, error			// Error EL1h
 
 	kernel_ventry	0, sync				// Synchronous 64-bit EL0
 	kernel_ventry	0, irq				// IRQ 64-bit EL0
-	kernel_ventry	0, fiq_invalid			// FIQ 64-bit EL0
+	kernel_ventry	0, fiq				// FIQ 64-bit EL0
 	kernel_ventry	0, error			// Error 64-bit EL0
 
 #ifdef CONFIG_COMPAT
 	kernel_ventry	0, sync_compat, 32		// Synchronous 32-bit EL0
 	kernel_ventry	0, irq_compat, 32		// IRQ 32-bit EL0
-	kernel_ventry	0, fiq_invalid_compat, 32	// FIQ 32-bit EL0
+	kernel_ventry	0, fiq_compat, 32		// FIQ 32-bit EL0
 	kernel_ventry	0, error_compat, 32		// Error 32-bit EL0
 #else
 	kernel_ventry	0, sync_invalid, 32		// Synchronous 32-bit EL0
@@ -658,6 +658,10 @@ SYM_CODE_START_LOCAL_NOALIGN(el1_sync)
 SYM_CODE_END(el1_sync)
 
 	.align	6
+SYM_CODE_START_LOCAL_NOALIGN(el1_fiq)
+alternative_if_not ARM64_NEEDS_FIQ
+	b	el1_fiq_invalid
+alternative_else_nop_endif
 SYM_CODE_START_LOCAL_NOALIGN(el1_irq)
 	kernel_entry 1
 	gic_prio_irq_setup pmr=x20, tmp=x1
@@ -688,6 +692,7 @@ alternative_else_nop_endif
 
 	kernel_exit 1
 SYM_CODE_END(el1_irq)
+SYM_CODE_END(el1_fiq)
 
 /*
  * EL0 mode handlers.
@@ -710,10 +715,15 @@ SYM_CODE_START_LOCAL_NOALIGN(el0_sync_compat)
 SYM_CODE_END(el0_sync_compat)
 
 	.align	6
+SYM_CODE_START_LOCAL_NOALIGN(el0_fiq_compat)
+alternative_if_not ARM64_NEEDS_FIQ
+	b	el0_fiq_invalid_compat
+alternative_else_nop_endif
 SYM_CODE_START_LOCAL_NOALIGN(el0_irq_compat)
 	kernel_entry 0, 32
 	b	el0_irq_naked
 SYM_CODE_END(el0_irq_compat)
+SYM_CODE_END(el0_fiq_compat)
 
 SYM_CODE_START_LOCAL_NOALIGN(el0_error_compat)
 	kernel_entry 0, 32
@@ -722,6 +732,10 @@ SYM_CODE_END(el0_error_compat)
 #endif
 
 	.align	6
+SYM_CODE_START_LOCAL_NOALIGN(el0_fiq)
+alternative_if_not ARM64_NEEDS_FIQ
+	b	el0_fiq_invalid
+alternative_else_nop_endif
 SYM_CODE_START_LOCAL_NOALIGN(el0_irq)
 	kernel_entry 0
 el0_irq_naked:
@@ -736,6 +750,7 @@ el0_irq_naked:
 
 	b	ret_to_user
 SYM_CODE_END(el0_irq)
+SYM_CODE_END(el0_fiq)
 
 SYM_CODE_START_LOCAL(el1_error)
 	kernel_entry 1
-- 
2.30.0